Fix printing of invalid flags argument of get_mempolicy syscall

* numa.c (SYS_FUNC(get_mempolicy)): Print 5th argument of syscall
using printxval_long.
diff --git a/numa.c b/numa.c
index b58a8fa..b46fc7f 100644
--- a/numa.c
+++ b/numa.c
@@ -111,7 +111,7 @@
 		tprintf(", %lu, ", tcp->u_arg[2]);
 		printaddr(tcp->u_arg[3]);
 		tprints(", ");
-		printflags(mempolicyflags, tcp->u_arg[4], "MPOL_???");
+		printflags_long(mempolicyflags, tcp->u_arg[4], "MPOL_???");
 	}
 	return 0;
 }